A three-dimensional warp-knitted fabric comprised of front and back ground structures and connecting yarns has superior resiliency, cushioning properties, and breathability, is therefore used in general clothing articles, sports wear, and underwear; as well as cushioning fabric for motor vehicle seats, chairs, and beds or the like in a field of interior furnishing. For achieving comfortability and breathability in these applications, disclosed are many technologies; and one among them is as follows. Different numbers of loops are employed in the front and back ground structures of the three-dimensional warp-knitted fabric. And, patterned indented surface is provided on the ground structure having a small number of loops as to decrease the area which comes into contact with the skin, in order for improving Breathability and texture.
For forming the patterned indented surface on the three-dimensional warp-knitted fabric, disclosed is a method of forming a ribbed pattern by applying high-pressure liquid flow on the knitted fabric (JP-B-1(1989)-40135 or Japanese Examined Patent Publication No. 1-40135). There is also disclosed a method of forming the pattern by heat pressing the knitted fabric with a calendar roll or the like (JP-A-4(1992)-146246 or Japanese. Unexamined Patent Publication No. 4-146246). In otherwise, proposed are methods such as one in which a three-dimensional pattern is formed by using thermally contracting yarns and performing heat treatment (JP-A-4(1992)-222260 and JP-A-4(1992)-327259).
However, the method of forming a ribbed pattern by the high pressure liquid flow has a problem in that it is difficult to maintain the shape of the ribbed patterns for a long time, whereas the method of heat pressing has a problem in that texture may be deteriorated by collapse of the knitted fabric or hardening of the front or back ground structure having only small numbers of loops. The method of using the thermally contracting yarns has a problem in that thickness-wise interval of the indents is relatively small and thus extent or feeling of indents on the surface is poor.
There is also a method for forming the patterned indented surface not by after-processing as above, but by pattern of knitting. For example, JP-A-9-137380 discloses a method of forming the patterned indented surface by mesh knitting, broad stitch, or tuck stitch.
However, while the patterned indented surface is surely obtained by these methods, the thickness-wise difference is relatively small, and hence the area of the projected portions which comes into contact with the skin is still large. Therefore, when it is applied to the motor vehicle's seat, it is insufficient for eliminating a feeling of stickiness or a feeling of steaminess due to sweating, for example, after seated for a long time in midsummer. Moreover, in the three-dimensional structure formed by the above-described methods, the density of kinitting, the number of loops, and intervals of loops are identical between the front and back ground structures. For this reason, sufficient effect is not achieved even when providing openings on the ground structures or when forming the indent pattern thereon by after-processing as in above.
After various investigations and trials, the inventors have found a way to solve the above described problems and to provide a three-dimensional warp-knitted fabric superior in breathability and cushioning properties, so as to complete the present invention.
In other words, it is an object of the present invention to provide a three-dimensional warp-knitted fabric which has following properties; light weight, high void ratio, high compressive elasticity, high breathability, and soft texture, as well as an agreeable structure which eliminates a feeling of being steamed and a feeling of sweating after long term use, as to be preferably used for motor vehicle's seats, chairs, and beds.